淮南潘集深部13-1煤层孔隙结构特征分析

发布时间：2018-03-09 15:03

本文选题：潘集深部煤层　切入点：压汞法　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：煤层孔隙作为煤层气的储存和运移场所,其结构特性决定了煤层的吸附性与含气性,对煤层孔隙结构特征的研究有利于煤层气的勘探和开发利用。本文以淮南潘集深部13-1煤层为研究对象,结合深部勘探资料和瓦斯地质资料,通过显微镜下观察、煤质工业分析、镜质组反射率等实验分析了煤层煤岩类型及煤质特征;通过扫描电镜、压汞实验、低温液氮吸附实验等实验方法,分析了煤层孔隙结构特征,并对该煤层孔隙结构特征差异发育进行了分析研究。研究区内13-1煤层其显微组分以镜质组为主;镜质组反射率多在0.70-0.95%之间,属于低变质烟煤至中变质烟煤阶段,一般以气煤、气肥煤为主。扫描电镜下可见植物组织孔、粒间孔、链间孔、气孔、溶蚀孔、晶间孔及铸模孔等,其中气孔和原生孔发育较明显,连通性较差;在遭到破坏的煤中外生孔较为发育,孔隙连通性较好,有利于提高煤层的渗透性能。压汞测试表明:研究区内13-1煤层孔隙度在3.07%-24.24%;其孔隙孔径分布整体上显示为两极分布,即以微、小孔占有优势,大孔其次,中孔的含量最少;孔隙形态以半封闭孔为主,连通性较差,其次在构造断裂带可见开放孔,在此区域内孔隙以大孔为主,中孔次之,孔隙连通性相对较好。低温液氮测试BET孔比表面积为0.05-4.01 m2/g,BJH总孔容值为0.0014-0.0163 cm3/g;可将其吸附曲线划分为半封闭孔、"墨水瓶"型孔和煤基质疏松的半封闭孔3种类型。煤层孔隙结构特征差异发育与煤变质程度、构造作用以及煤层埋藏深度存在一定的关系,其中煤层煤变质程度为孔隙结构特征发育的主控因素。此外,孔隙结构特征差异发育对煤层吸附性和含气性有一定的影响,在相同条件下,同一孔径段内BET表面积越大,其吸附性越强;瓦斯含气总量主要来自于微孔与小孔中的吸附瓦斯。
[Abstract]:As the storage and migration place of coalbed methane, the pore structure of coal seam determines the absorption and gas content of coal bed. The study of pore structure characteristics of coal seam is beneficial to the exploration and exploitation of coalbed methane. This paper takes the deep 13-1 coal seam in Panji of Huainan as the research object, combines the deep exploration data and the gas geology data, through the microscope observation, the coal quality industry analysis, The types and characteristics of coal seam are analyzed by vitrinite reflectance, and the pore structure of coal seam is analyzed by SEM, mercury injection test, low temperature liquid nitrogen adsorption experiment and so on. In the study area, the macerals of 13-1 coal seam are mainly vitrinite, and the reflectance of vitrinite is between 0.70-0.95%, which belongs to the stage of low metamorphic bituminous coal to medium metamorphic bituminous coal, and generally takes gas coal. Under scanning electron microscope, plant tissue pore, intergranular pore, interchain pore, pore, solution pore, intergranular pore and mold pore were found, among which stomata and primary pores developed obviously and connectivity was poor. The porosity of 13-1 coal seam is 3.07-24.24, and the pore pore size distribution of the coal seam 13-1 in the study area shows that the pore size distribution is bipolar, and the permeability of the coal seam is improved by mercury injection test, and the porosity of the damaged coal is better than that of the other coal mines, and the porosity of coal seam 13-1 is in the range of 3.07-24.24. That is to say, micropore, micropore is dominant, macropore is second, mesopore is the least, pore morphology is mainly semi-closed pore, connectivity is poor, open pore is seen in structural fault zone, pore in this area is dominated by macropore, mesopore is the second. The specific surface area of BET pore measured by liquid nitrogen at low temperature is 0.05-4.01 m ~ (-2) 路g ~ (-1) 路g ~ (-1). The total pore volume value of BJH is 0.0014-0.0163 cm ~ (3) / g. The adsorption curve can be divided into three types: semi-closed pore, "ink bottle" pore and loose semi-closed pore of coal matrix. Differences in pore structure and coal metamorphism, There is a certain relationship between tectonic process and buried depth of coal seam, in which coal metamorphic degree is the main controlling factor for the development of pore structure characteristics. In addition, the difference development of pore structure characteristics has a certain influence on coal seam adsorption and gas-bearing properties. Under the same conditions, the larger the surface area of BET in the same pore area, the stronger the adsorption, and the total gas content of gas mainly comes from the adsorbed gas in micropores and pores.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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